Non-destructive 3D analysis of the structure and interfaces of a monolithic solid oxide cell stack

Solid oxide cells (SOC) will play an important role in green energy conversion. This work focuses on a novel monolithic SOC stack design that optimizes the use of raw materials and boosts the power density. The monolithic stack is sintered as one unit and cannot be disassembled without it being destroyed. X-ray μCT was used for non-destructive 3D characterization of the internal structure. Visualization of the entire monolith was used for studying the gas channels. Internal scans at higher spatial resolution revealed the structure of the individual cell layers and the micropore structure of the support layers. 3D X-ray imaging was found useful for analyzing the gas transport properties including pore size distribution, tortuosity and connectivity as well as contact areas between the layers. In addition, the method is useful for quality control, particularly for the identification of microcracks and delaminations.